Dale T. Mortensen, a recent Nobel laureate and the Board of Trustees Professor of Economics at Northwestern University in the Weinberg College of Arts and Sciences, died on January 9, surrounded by his family. He was 74.

Mortensen pioneered a new approach to studying important economic problems now known as search theory. Utilizing the theory, Mortensen developed an original approach to investigating the labor market, revolutionizing how economists and policymakers view labor market matters and the role of government policy and regulation.

That original approach can, for example, explain why it takes so long for job seekers to find acceptable jobs even in good economic times, when vacancies are plentiful, or why firms with vacancies fail to fill positions quickly even though large numbers of people are unemployed.

Macroeconomists cite Mortensen's work as a key element in understanding how unemployment changes during the cycle. Search theory has since been applied to a host of other major areas of economics such as monetary theory, housing markets, marriage markets and many others.

"On behalf of the entire Northwestern community, I extend my deep condolences to Professor Mortensen’s family," said Northwestern President Morton Schapiro. "He will be deeply missed by his colleagues at Northwestern — and by the world. His groundbreaking work is especially relevant to policymakers attempting to address unemployment today."